Add an opinionated C++20 adapter

3 files changed, 350 insertions, 1 deletions

diff --git a/cpp/nissy.cpp b/cpp/nissy.cpp
new file mode 100644
index 0000000..7987f6c
--- /dev/null
+++ b/cpp/nissy.cpp
@@ -0,0 +1,216 @@
+/*
+C++20 interface for nissy.
+
+TODO: add more documentation (here and in README.md)
+*/
+
+#include "./nissy.h"
+
+extern "C" {
+        long long nissy_compose(const char *, const char *, char *);
+        long long nissy_inverse(const char *, char *);
+        long long nissy_applymoves(const char *, const char *, char *);
+        long long nissy_applytrans(const char *, const char *, char *);
+        long long nissy_convert(const char *, const char *, const char *,
+            unsigned, char *);
+        long long nissy_getcube(long long, long long, long long, long long,
+            const char *, char *);
+        long long nissy_solverinfo(const char *, char *);
+        long long nissy_gendata(const char *, unsigned long long, char *);
+        long long nissy_checkdata(unsigned long long, const char *);
+        long long nissy_solve(const char *, const char *, unsigned, unsigned,
+            unsigned, unsigned, int, int, unsigned long long, const char *,
+            unsigned, char *, long long *);
+        long long nissy_countmoves(const char *);
+        long long nissy_setlogger(void (*)(const char *));
+}
+
+namespace nissy {
+        namespace utils {
+                void fixstr(std::string& str)
+                {
+                        size_t n = str.find('\0');
+                        str.resize(n);
+                }
+
+                std::variant<cube_t, error_t>
+                    cube_or_error(const char *r, long long e)
+                {
+                        if (e < 0)
+                                return error_t{e};
+                        return cube_t{r};
+                }
+
+                std::variant<std::string, error_t>
+                    string_or_error(const char *cstr, long long e)
+                {
+                        if (e < 0)
+                                return error_t{e};
+
+                        std::string str{cstr};
+                        fixstr(str);
+                        return str;
+                }
+
+                std::function<void(const char *)>
+                    char_str_fn(std::function<void(std::string&)> f)
+                {
+                        return [&](const char *cc){
+                                std::string str{cc};
+                                f(str);
+                        };
+                }
+        }
+        
+        std::variant<cube_t, error_t>
+        compose(const cube_t& cube, const cube_t& permutation)
+        {
+                char result[size::B32];
+
+                auto error = nissy_compose(cube.value.c_str(),
+                    permutation.value.c_str(), result);
+
+                return utils::cube_or_error(result, error);
+        }
+
+        std::variant<cube_t, error_t>
+        inverse(const cube_t& cube)
+        {
+                char result[size::B32];
+
+                auto error = nissy_inverse(cube.value.c_str(), result);
+
+                return utils::cube_or_error(result, error);
+        }
+
+        std::variant<cube_t, error_t>
+        applymoves(const cube_t& cube, const moves_t& moves)
+        {
+                char result[size::B32];
+
+                auto error = nissy_applymoves(cube.value.c_str(),
+                    moves.value.c_str(), result);
+
+                return utils::cube_or_error(result, error);
+        }
+
+        std::variant<cube_t, error_t>
+        applytrans(const cube_t& cube, const trans_t& trans)
+        {
+                char result[size::B32];
+
+                auto error = nissy_applytrans(cube.value.c_str(),
+                    trans.value.c_str(), result);
+
+                return utils::cube_or_error(result, error);
+        }
+
+        std::variant<std::string, error_t>
+        convert(const cube_format_t& format_in,
+            const cube_format_t& format_out, const std::string& cube_string)
+        {
+                char result[size::CUBE_MAX];
+
+                auto error = nissy_convert(format_in.value.c_str(),
+                    format_out.value.c_str(), cube_string.c_str(),
+                    size::CUBE_MAX, result);
+
+                return utils::string_or_error(result, error);
+        }
+
+        std::variant<cube_t, error_t>
+        getcube(long long ep, long long eo, long long cp, long long co,
+            const std::string& options)
+        {
+                char result[size::B32];
+
+                auto error = nissy_getcube(ep, eo, cp, co, options.c_str(),
+                    result);
+
+                return utils::cube_or_error(result, error);
+        }
+
+        std::variant<std::pair<size_t, std::string>, error_t>
+        solverinfo(const solver_t& solver)
+        {
+                char dataid[size::DATAID];
+
+                auto error = nissy_solverinfo(solver.value.c_str(), dataid);
+                if (error < 0)
+                        return error_t{error};
+
+                return std::pair{error, dataid};
+        }
+
+        std::variant<solver_data_t, error_t>
+        gendata(const solver_t& solver)
+        {
+                char dataid[size::DATAID];
+
+                auto error = nissy_solverinfo(solver.value.c_str(), dataid);
+                if (error < 0)
+                        return error_t{error};
+
+                size_t sz = error;
+                std::vector<std::byte> buffer(sz);
+                error = nissy_gendata(solver.value.c_str(), sz,
+                    reinterpret_cast<char *>(buffer.data()));
+                if (error < 0)
+                        return error_t{error};
+
+                return solver_data_t{buffer};
+        }
+
+        std::optional<error_t>
+        checkdata(const solver_data_t& data)
+        {
+                auto error = nissy_checkdata(data.value.size(),
+                    reinterpret_cast<const char *>(data.value.data()));
+
+                if (error < 0)
+                        return error_t{error};
+                return std::nullopt;
+        }
+
+        std::variant<solve_result_t, error_t>
+        solve(const cube_t& cube, const solver_t& solver,
+            nissflag_t niss, unsigned minmoves, unsigned maxmoves,
+            unsigned maxsolutions, int optimal, int threads,
+            const solver_data_t& data)
+        {
+                const size_t len = 3 * (maxmoves+1) * maxsolutions;
+                char csols[len];
+                long long cstats[size::SOLVE_STATS];
+
+                auto error = nissy_solve(cube.value.c_str(),
+                    solver.value.c_str(), niss.value, minmoves, maxmoves,
+                    maxsolutions, optimal, threads, data.value.size(),
+                    reinterpret_cast<const char *>(data.value.data()),
+                    len, csols, cstats);
+
+                if (error < 0)
+                        return error_t{error};
+
+                std::vector<std::string> sols;
+                std::string_view strsols(csols);
+                for (auto r : strsols | std::views::split('\n'))
+                        sols.push_back(std::string{r.begin(), r.end()});
+
+                return solve_result_t{sols, std::to_array(cstats)};
+        }
+
+        std::variant<unsigned, error_t>
+        countmoves(const moves_t& moves)
+        {
+                auto error = nissy_countmoves(moves.value.c_str());
+                if (error < 0)
+                        return error_t{error};
+                return (unsigned)error;
+        }
+
+        void setlogger(std::function<void(std::string&)> log)
+        {
+                nissy_setlogger(
+                    utils::char_str_fn(log).target<void(const char *)>());
+        }
+}
diff --git a/cpp/nissy.h b/cpp/nissy.h
new file mode 100644
index 0000000..e336c7a
--- /dev/null
+++ b/cpp/nissy.h
@@ -0,0 +1,133 @@
+/*
+C++20 header file for nissy.
+*/
+
+#ifndef NISSY_H
+#define NISSY_H
+
+#include <array>
+#include <functional>
+#include <optional>
+#include <ranges>
+#include <string>
+#include <string_view>
+#include <variant>
+#include <vector>
+
+namespace nissy {
+        /* Some constants for size for I/O buffers */
+        namespace size {
+                constexpr size_t B32 = 22;
+                constexpr size_t H48 = 88;
+                constexpr size_t CUBE_MAX = H48;
+                constexpr size_t TRANSFORMATION = 12;
+                constexpr size_t SOLVE_STATS = 10;
+                constexpr size_t DATAID = 255;
+        }
+
+        /* Some structs definitions for better type safety */
+        struct nissflag_t { unsigned value; };
+        struct error_t { long long value; };
+        struct cube_t { std::string value; };
+        struct moves_t { std::string value; };
+        struct trans_t { std::string value; };
+        struct cube_format_t { std::string value; };
+        struct solver_t { std::string value; };
+        struct solver_data_t { std::vector<std::byte> value; };
+        struct solve_result_t {
+                std::vector<std::string> solutions;
+                std::array<long long, size::SOLVE_STATS> stats;
+        };
+
+        /* Flags for NISS options */
+        namespace nissflag {
+                constexpr nissflag_t NORMAL{1};
+                constexpr nissflag_t INVERSE{2};
+                constexpr nissflag_t MIXED{4};
+                constexpr nissflag_t LINEAR{NORMAL.value | INVERSE.value};
+                constexpr nissflag_t ALL{LINEAR.value | MIXED.value};
+        }
+
+        /* Error codes */
+        namespace error {
+                constexpr error_t UNSOLVABLE{-1};
+                constexpr error_t INVALID_CUBE{-10};
+                constexpr error_t UNSOLVABLE_CUBE{-11};
+                constexpr error_t INVALID_MOVES{-20};
+                constexpr error_t INVALID_TRANS{-30};
+                constexpr error_t INVALID_FORMAT{-40};
+                constexpr error_t INVALID_SOLVER{-50};
+                constexpr error_t NULL_POINTER{-60};
+                constexpr error_t BUFFER_SIZE{-61};
+                constexpr error_t DATA{-70};
+                constexpr error_t OPTIONS{-80};
+                constexpr error_t UNKNOWN{-999};
+        }
+
+        /* Cube constants */
+        namespace cube {
+                const cube_t SOLVED{"ABCDEFGH=ABCDEFGHIJKL"};
+        }
+
+        std::variant<cube_t, error_t> inverse(
+                const cube_t& cube
+        );
+
+        std::variant<cube_t, error_t> applymoves(
+                const cube_t& cube,
+                const moves_t& moves
+        );
+
+        std::variant<cube_t, error_t> applytrans(
+                const cube_t& cube,
+                const trans_t& trans
+        );
+
+        std::variant<std::string, error_t> convert(
+                const cube_format_t& format_in,
+                const cube_format_t& format_out,
+                const std::string& cube_string
+        );
+
+        std::variant<cube_t, error_t> getcube(
+                long long ep,
+                long long eo,
+                long long cp,
+                long long co,
+                const std::string& options
+        );
+
+        std::variant<std::pair<size_t, std::string>, error_t> solverinfo(
+                const solver_t& solver
+        );
+
+        std::variant<solver_data_t, error_t> gendata(
+                const solver_t& solver
+        );
+
+        std::optional<error_t> checkdata(
+                const solver_data_t& data
+        );
+
+        std::variant<solve_result_t, error_t> solve(
+                const cube_t& cube,
+                const solver_t& solver,
+                nissflag_t niss,
+                unsigned minmoves,
+                unsigned maxmoves,
+                unsigned maxsolutions,
+                int optimal,
+                int threads,
+                const solver_data_t& data
+        );
+
+        std::variant<unsigned, error_t> countmoves(
+                const moves_t& moves
+        );
+
+        void setlogger(
+                std::function<void(std::string&)> log
+        );
+}
+
+#endif
diff --git a/src/nissy.h b/src/nissy.h
index a6a0ac1..816e03a 100644
--- a/src/nissy.h
+++ b/src/nissy.h
@@ -23,6 +23,7 @@ for example 'rotation UF' or 'mirrored BL'.
 /* Some constants for size for I/O buffers */
 #define NISSY_SIZE_B32            22U
 #define NISSY_SIZE_H48            88U
+#define NISSY_SIZE_CUBE_MAX       NISSY_SIZE_H48
 #define NISSY_SIZE_TRANSFORMATION 12U
 #define NISSY_SIZE_SOLVE_STATS    10U
 #define NISSY_SIZE_DATAID         255U
@@ -39,7 +40,6 @@ for example 'rotation UF' or 'mirrored BL'.
 /* The solved cube in B32 format */
 #define NISSY_SOLVED_CUBE "ABCDEFGH=ABCDEFGHIJKL"
 
-
 /* Error codes ***************************************************************/
 
 /*